Articulated beds or bed frames for the home market have not heretofore achieved significant commercial success and such beds have for the most part been marketed as a hospital or nursing home product and with such objectives have been over designed and overly complicated and as a result have been too costly for the residential or home market for articulated beds.
Over the last several decades articulated chairs and sofas have achieved some commercial success in the residential market but only recently has such technology been adapted for the residential articulated bed marketplace.
A primary consideration in the design of articulated beds and components therefore in the residential market is ease of shipment because a container the size of an entire complete articulated bed assembly would not only be excessively large but too heavy for a single delivery person to bring into the home to install.
One attempt at solving this problem is illustrated in the Elliott, U.S. Pat. No. 4,381,571 which shows an articulated mattress spring that is adapted to fit on top of and rest on a separate simple rectangular bed frame. The Elliott power drive module or mattress frame includes large stationary "L" shaped side sections with cross members to provide support for axial oriented motor and screw assemblies that drive complicated four bar linkages at the four corners of the module that serve to raise and lower the head and leg sections of the mattress support. While Elliott suggests that these parts, numbering literally hundreds, may be disassembled for shipment, it is realistically not practical to have the purchaser reassemble this complex drive in his or her home.
A similar articulated bed is illustrated in the Neumann, U.S. Pat. No. 4,120,057 and it shows a power system for an articulated mattress support and, like the Elliott design, is adapted to fit into a bed frame. The problem with the Neumann device is that it requires a large rectangular frame the size of the bed frame itself so that no size reduction is practically possible in the Neumann system.
Furthermore, in the Neumann device the power module with drive motors, gearing and rocker shafts, requires that the rocker shafts be mounted in outboard bearings, i.e. bearings in the large rectangular frame described above and such outboard bearings denigrate the capability of shipping the power module in easily carried containers without requiring any significant reassembly at the purchaser's location.
Other articulated beds are illustrated in the Muir, U.S. Pat. No. 1,397,773 and the Szemplak, et al., U.S. Pat. No. 3,051,965. The patent to Muir also shows a device for adjusting the articulated bed. Double motor-type systems are shown in the Taylor, U.S. Pat. No. 2,500,742. Another standard articulated bed frame is illustrated in Hanning, et al., U.S. Pat. No. 3,921,230.
An important disadvantage in the above described articulated beds is that they do not readily fold up for transport without a significant amount of disassembly. Of course, folding beds with the head and foot sections articulated approximately at the mid-point of the bed frame so that the head and foot sections can meet one another and assume a generally planar vertical orientation for rolling on casters have been in the marketplace for many decades. However, this technology is not insofar as we are aware been applied to beds with articulated head and leg sections.
A foldable articulated bed would be desirable because of the manner of marketing and shipping articulated beds into the residential market. If the bed is foldable, it is far easier to transport and bring into the purchaser's home and set up with a minimum of assembly, and in many cases by the purchasers themselves.
Another disadvantage in prior articulated beds results from the motorized drive assemblies for the head and foot sections. Because articulation is frequently, if not usually, effected while the user is lying on the bed itself, a significant amount of torque must be provided by the head and foot platform drive units. As the head and foot platforms are lowered from their raised positions, there is a possibility of trapping fingers or arms between these descending platforms and the bed frame itself.
A further disadvantage in these prior articulated bed assemblies is that they must be carried into the purchaser's residence and because of their motorized configuration, they are quite heavy and frequently require two people to carry them into the purchaser's home as a unit without any disassembly.
It is a primary object of the present invention to ameliorate the problems noted above in prior art articulated bed assemblies.